I was having constant crashes with Flash 13 and tracked it down to HTTPS Everywhere extension. (Disconnect works fine)
But the problem with Flash 13 is invisible audio advertisements, pop-unders, commercials that can't be blocked on most sites by a combo of Ghostery, AdBlock AdBlockPlus, and Disconnect that became intolerable. Adobe has opened up security holes for the advertisers that AdBlockers on Chromium can't adapt to.
I went back to Flash stable 11.7 and ALL those problems disappear
but I was still getting Flash crashes on Iron 34 but not in PaleMoon or Firefox.
Again, most all the crashes stop when I turned off HTTPS Everywhere.
Shame that. I'll just have to watch the lock on the address bar before I log in anywhere and flip HTTPS Everywhere on if the lock is missing.
There is no way I'm using Flash 13. Hopefully (but I doubt it) Flash 14 will close some security holes otherwise stuck at Flash 11.7 till they do something to make me leave it.